a) Field of the Invention
This invention relates to deodorant and antimicrobial dispersions, and more specifically, to deodorant and antimicrobial dispersions useful by themselves as liquid deodorant and antimicrobial agents and useful for imparting deodorizing power and antimicrobial activity to various base materials such as paints, synthetic fibers, synthetic resins and paper.
b) Description of the Related Art
Numerous deodorant and antimicrobial agents have been used to date in various fields. In particular, a variety of products such as films, wall paper, decorated plywood, building materials, fibers, nonwoven fabrics and clothing are required neither to give off offensive odor nor to permit growth of bacteria, fungi and the like, that is, to have so-called deodorizing power and antimicrobial activity in many instances.
In recent years, there is an ever-increasing demand for the amenity of living space. In view of the crowding of houses due to urbanization and also of the living environment of a closed house or building structure constructed of concrete and aluminum sash windows, it has become an indispensable condition for clean-environment life that visual, olfactory and hygienic unpleasant feeling be removed.
Described specifically, formaldehyde-linked health disturbances have posed problems in recent years. The odor of formaldehyde has already become a social problem as xe2x80x9csick house syndromexe2x80x9d in a living environment of a closed house structure, especially in a newly-built house. This problem is attributed to formaldehyde given off from newly-developed building materials. Various productsxe2x80x94such as wall paper, decorated plywood, building materials, fibers, nonwoven fabrics and clothingxe2x80x94are hence required to have a function to remove formaldehyde. Further, from the viewpoint of, such products are also required to be equipped with an antimicrobial and antifungal function.
An object of the present invention is, therefore, to provide a deodorant and antimicrobial dispersion which can impart excellent deodorizing power and antimicrobial activity to various materials.
The above-described object can be achieved by the present invention to be described subsequently herein. Namely, the present invention provides a deodorant and antimicrobial dispersion comprising a deodorant and antimicrobial component, a binder resin and an aqueous or oily liquid medium, wherein the deodorant and antimicrobial component comprises an oxide or hydroxide of an alkaline earth metal, hydrated silica, and a cationic surfactant.
The deodorant and antimicrobial dispersion can be obtained by dispersing the specific deodorant and antimicrobial component in the aqueous or oily liquid medium in which the binder resin is contained. The dispersion can be sprayed without causing contamination. Especially, the deodorant and antimicrobial dispersion can be preferably used for the a production of base paper for decorated facing plates, woven fabrics, base paper for wall paper, and the like, all of which are provided with deodorizing power and antimicrobial activity.
The deodorant and antimicrobial dispersion is effective for the deodorization of acetoaldehyde odor, formaldehyde odor, acetic acid odor and the like out of various offensive odors and also for the inhibition of growth of bacteria, fungi and the like. Further, the deodorant and antimicrobial dispersion according to the present invention can impart excellent deodorizing power and antimicrobial activity to various materials.
The present invention will next be described more specifically based on preferred embodiments.
The deodorant and antimicrobial component, which makes up the deodorant and antimicrobial dispersion according to the present invention, comprises, in combination, an oxide or hydroxide of an alkaline earth metal, hydrated silica, and a cationic surfactant. Illustrative of the alkaline earth metal oxide or hydroxide are the oxides and hydroxides of barium, calcium, magnesium and the like, with magnesium hydroxide being particularly effective.
This alkaline earth metal oxide or hydroxide may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial component is supposed to be 100 parts by weight, it amounts to 80 to 40 parts by weight. A proportion of the alkaline earth metal oxide or hydroxide smaller than the above range leads to insufficient performance in that conversion of aldehydes, especially formaldehyde into formose becomes slower. On the other hand, a proportion of the alkaline earth metal oxide or hydroxide greater than the above range also leads to insufficient performance in that the proportion of a substance adapted to undergo an addition reaction with formaldehyde for the removal of formaldehyde, that is, the cationic surfactant in the composition decreases, thereby lowering the deodorizing reaction velocity of aldehydes and resulting in insufficient fast-acting property.
The hydrated silica for use in the present invention is represented by the empirical formula SiO2.nH2O, and is in the form of secondary particles formed as a result of flocculation of fine silica particles having many silanol groups on surfaces thereof. Such hydrated silica is a flocculate of ultrafine particles of hydrated silica, which is available from a reaction of sodium silicate with a mineral acid, and contains a number of voids between particles. These voids effectively act for the adsorption of offensive odor components. Upon production of deodorant and antimicrobial, decorated facing plates, these voids also contribute to improvements in the impregnation of the hydrated silica with a base material for the decorated facing plates, such as a melamine resin, polyester resin or urethane resin, which is used in the production.
Such hydrated silica is available, for example, from Mizusawa Industrial Chemicals, Inc., Tokyo, Japan under the trade names of xe2x80x9cP-801xe2x80x9d, xe2x80x9cP-802xe2x80x9d, xe2x80x9cP-526xe2x80x9d, xe2x80x9cP-527xe2x80x9d, xe2x80x9cP-603xe2x80x9d, xe2x80x9cP-604xe2x80x9d, xe2x80x9cP-554Axe2x80x9d, xe2x80x9cP-73xe2x80x9d, xe2x80x9cP-78Axe2x80x9d, xe2x80x9cP-78Dxe2x80x9d, xe2x80x9cP-78Fxe2x80x9d, xe2x80x9cP-707xe2x80x9d, xe2x80x9cP-740xe2x80x9d, xe2x80x9cP-752xe2x80x9d, xe2x80x9cP-50xe2x80x9d, xe2x80x9cP-766xe2x80x9d, xe2x80x9cC-1xe2x80x9d, xe2x80x9cS-0xe2x80x9d, xe2x80x9cNP-8xe2x80x9d, xe2x80x9cP-802Yxe2x80x9d, xe2x80x9cP-832xe2x80x9d, xe2x80x9cP-87xe2x80x9d, xe2x80x9cP-363xe2x80x9d, xe2x80x9cC-002xe2x80x9d, xe2x80x9cC-402xe2x80x9d and xe2x80x9cC-484xe2x80x9d, all of which are usable in the present invention.
The above-described hydrated silica may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial component is supposed to be 100 parts by weight, it amounts to 50 to 10 parts by weight. A proportion of the hydrated silica smaller than the above range leads to insufficient performance in that the deodorizing reaction velocity of aldehydes becomes slower, resulting in insufficient fast-acting property. On the other hand, a proportion of the hydrated silica greater than the above range also leads to insufficient performance in that, when used in paints or the like, the paints and the like are provided with poor flowability and especially, with insufficient shelf stability.
As the cationic surfactant for use in the present invention, one represented by the empirical formula HOxe2x80x94Rxe2x80x94NHCH2CH2OH in which R is a C12-C14 alkylene group is preferred. The cationic surfactant reacts with an aldehyde group of formaldehyde or the like, thereby converting such an aldehyde compound into an odorless compound.
Such cationic surfactants are available from Miyoshi Oil and Fat Co., Ltd., Tokyo, Japan under the trade names of xe2x80x9cMiyocol 368Exe2x80x9d, xe2x80x9cMiyocol QX-33Nxe2x80x9d, xe2x80x9cDuspar 125Bxe2x80x9d, xe2x80x9cDuspar 125Bxe2x80x9d, xe2x80x9cDuspar 125Bxe2x80x9d and xe2x80x9cDuspar 1400Bxe2x80x9d, all of which are usable in the present invention.
The above-described cationic surfactants can be used either singly or in combination. They, however, include some compounds which, when formed into dispersions, may not be sufficient in dispersibility, stability, thermal stability, light fastness, processability and/or the like. Upon using the deodorant and antimicrobial dispersion of this invention for various applications, heat resistance is also important in connection with processability. From this viewpoint, xe2x80x9cDuspar 125Bxe2x80x9d and xe2x80x9cDuspar 125BNxe2x80x9d are particularly preferred.
The above-described cationic surfactant may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial component is supposed to be 100 parts by weight, it amounts to 0.1 to 30 parts by weight. If the cationic surfactant is used in a proportion smaller than the above range, the resulting composition is insufficient in performance in that the velocity of deodorizing reaction with aldehydes becomes slower and the fast-acting property is insufficient. If the cationic surfactant is used in a proportion greater than the above range, on the other hand, the resulting deodorant and antimicrobial dispersion is insufficient in performance in that, when it is used in a paint, coated films are provided with reduced physical properties and especially, insufficient resin impregnation, insufficient hardening and the like take place upon forming melamine facing plates.
The deodorant and antimicrobial dispersion according to the present invention can be obtained by dispersing the deodorant and antimicrobial component in the aqueous or oily liquid medium which contains the binder resin. Examples of the aqueous liquid medium can include water, and mixtures of water water-soluble organic solvents. Illustrative of such water-soluble organic solvents are methanol, ethanol, propanol, acetone, methyl ethyl ketone, ethylene glycol, diethylene alcohol, their acetates and lower alcohol ethers, dioxane, pyrrolidone, dimethylformamide, formamide, and dimethyl sulfoxide.
On the other hand, examples of the oily liquid medium can include organic solvents commonly employed in paints and printing inks. Specific examples can include ketones such as acetone, methyl ethyl ketoneandmethyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, methyl lactate and butyl acetate; hydrocarbons such as toluene and xylene; and other organic solvents.
As illustrative binder resins for use in the present invention, acrylic resins, vinyl acetate resin, and binder resins used in a variety of conventional water-based paints and printing inks are all usable. The binder resin may be added at any concentration, but in general, may preferably be added in a proportion of from 10 to 1,000 parts by weight per 100 parts by weight of the deodorant and antimicrobial component. The binder resin may be dissolved in the aqueous or oily liquid medium, or may be dispersed or emulsified in the liquid medium.
The deodorant and antimicrobial dispersion according to the present invention can be obtained by dissolving or dispersing the deodorant and antimicrobial component in the liquid medium containing the conventionally-known binder resin such that the concentration of the deodorant and antimicrobial component falls preferably within a range of from about 5 to 50 wt. %, more preferably within a range of from 10 to 30 wt. % in terms of solids. A colorant such as a dye or pigment can also be added to the deodorant and antimicrobial dispersion according to the present invention.
To disperse or dissolve the deodorant and antimicrobial component in the aqueous or oily liquid medium containing the binder resin, dispersers conventionally used in the technical field of pigment dispersion, such as ball mills, speed line mills, sandmills, roll mills and paint shakers, are all usable.